> Not so long ago I read a history here in HN about a guy that first coded in his head, then wrote everything in paper, and finally coded in a computer. It compiled without errors. Slow pusher? Inefficient?

I've read and heard stories about these folks too, apparently this was more common decades ago.

To be clear, I don't think I could pull it off with any language. It's quite impressive and admirable to get things right on the first try.

Having said that, the thing is, languages were a lot simpler back then too. I'm not convinced this is realistically even possible with today's languages unless you constrain yourself to some overly restrictive subset. Like try this with C++, and I would be shocked if you can write nontrivial programs without getting compiler errors. Like to give a trivial example, every time I write my own iterator class for a container, I miss something when I hit compile: like either a comparison operator, or subtraction, or conversion to const iterator, or post-decrement, or subscript, or some member typedef. Or try it with python, and I bet you'll call .get() on something and then forget to check for null somewhere.

I would love to be proven wrong though. If anyone knows of someone who does this with a modern language, please share.